fix: apt-install cmake + build-essential before llama.cpp build

convert_gguf.py

@@ -58,7 +58,11 @@ def main() -> None:
         str(merged_dir), "--outtype", "f16", "--outfile", str(f16_path),
     ], check=True)
 
-    print(f"[5/5] Building quantize binary and writing {QUANTIZE.upper()}")
+    print(f"[5/5] Installing build tools + building quantize binary, writing {QUANTIZE.upper()}")
+    # The uv Docker image (python3.12-bookworm) has no cmake by default. Install
+    # via apt (container runs as root). build-essential brings gcc/g++/make.
+    subprocess.run(["apt-get", "update", "-qq"], check=True)
+    subprocess.run(["apt-get", "install", "-y", "-qq", "cmake", "build-essential"], check=True)
     subprocess.run(["cmake", "-B", "llama.cpp/build", "llama.cpp"], check=True)
     subprocess.run(["cmake", "--build", "llama.cpp/build", "--target", "llama-quantize", "-j"], check=True)
     quantize_bin = "llama.cpp/build/bin/llama-quantize"